diff -up src/module_list.py.orig src/module_list.py --- src/module_list.py.orig 2014-11-18 15:29:30.360131313 -0200 +++ src/module_list.py 2014-11-18 15:29:37.432131407 -0200 @@ -2130,7 +2130,7 @@ ext_modules = [ def is_package_installed(name): return False -if is_package_installed('fes'): +if 1: ext_modules.extend([ Extension("sage.libs.fes", ["sage/libs/fes.pyx"],